(800) 853-2651
SHOP NOW

Sealing Exhaust Manifold Leak

C

Chuck / MI

New User
Have a 1966 MM M670 tractor with gasoline engine. Noticed exhaust leakage between the cylinder head and the exhaust manifold. Removed the manifolds and it appears that all four cylinders leaked. The gaskets likely are several decades old. There is erosional/corrosional damage to both the cast iron manifold and the mating surfaces of the cylinder heads. The NOS gaskets I have are 0.040+ in thickness, however, I am questioning if that will be adequate to fill the gaps. Do I use high-temp RTV sealer on both sides of gasket? Or is there a better means of ensuring a reasonably long-lived seal? I'd appreciate hearing of your experience in dealing with this issue. Thanks . . . Chuck
 
Bought a sealer from napa awhile back, acoustic seal, had real good luck with it. Comes in a white toothpaste container.
 
I had that on a WD 45 bad enough that I touched up the head with flux cored mig welding, while it was still assembled on the motor. Took the manifold to a local machine shop that would hold it on a wide belt sander, as opposed to setting it up on a vertical mill. only took a few minutes and 10 bucks. I would think that a sealer would need to be something like wood stove gasket sealer.
 
well if you dont want to go all the way and have the surfaces machined flat then use muffler cement. it comes in a squeeze out tube. its like soft cement then hardens with the heat. i have used it and it does work. rtv sealer is not for that. as i say use the stuff that its designed for.
 
Have you checked across the manifold ports with a straight edge?

I believe that is a one piece manifold. If there is a difference in the heights of the ports where they mate to the head, there is a danger of cracking the manifold when tightening it down.

If you have a steady hand and a good eye, you 'might' be able to true it up somewhat with a belt sander. But be very careful, trust the straight edge, not what looks good. Go slow and be very careful not to make it worse.

It's hard to have something like that milled as there is no practical way to hold the manifold to the table.

Or clean everything up, get all the rust scale and gasket residue off the head and manifold. Prep all the bolts, studs, nuts so they screw together freely, then go back with a new gasket. Cautiously tighten it evenly. Then retighten it a couple times while it's hot.

Used to could buy muffler sealer in a tube. Not sure it's even made any more. It was useless as muffler sealer but made good high temp gasket sealer. No RTV can handle the exhaust temps.
 
The manifold can be machined or sanded as Little ed indicates, I would wire brush the head surface and fill the voids with JB weld. It does not need to hold parts together, it needs to be a filler in the eroded areas, being captured by the gasket. I would not do the JB weld idea if the erosion was in a continuous groove from inside to outside of the head. In that case the use of Ni rod SMAW in those spots followed by flat filing the material to resurface it would work. Jim
 
Take the manifold to a machine shop and have them dress it up . as for the heads depending how bad they are a new gskt will likely fix the problem . Once installed and tightened down alow it to come up to running temp and retighten and keep and eye on the nuts as it does take a while for everything to set in .
 
I think this the way to fix it ,cleanup cut .
Then when torqued down evenly ,less like to crack it over r torque to seal uneven surface . Manifolds are getting very hard to find. I think
 
Back when I had more time than money I surfaced a WD Allis manifold with a large file. The most material has to come off the intake runners. I checked my progress with a framing square
 
You must log in or register to reply here.

Similar threads

0
Exhaust Manifold Leak/Repair On A 51
Replies
9
Views
1K
00_Green
0
O
Farmall Super M-TA exhaust manifold leak
Replies
9
Views
3K
oldfarmall
O
K
1650 Gas Manifold Question
Replies
3
Views
834
Kerwin
K
F
super 88 exhaust manifold
Replies
3
Views
591
Fatjay
F
M
8N - Exhaust Manifold Leak Gasket Questions
Replies
14
Views
12K
Greybeard - PA
G
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top